Medium-range order as an intrinsic property of Co-rich amorphous alloys
Departamento de Electricidad y Electrónica, Facultad de Ciencias,
Universidad del País Vasco - Apartado 644, 48080 Bilbao, Spain
Accepted: 12 August 1997
X-ray absorption spectroscopy has been used to study the short-range order of some Fe-Co–based amorphous alloys with low Fe concentration prepared by two different methods: melt spinning (FeCoSiB) and electrodeposition (FeCoP). A qualitative analysis of the near-edge region points clearly to the existence of a well-defined chemical affinity of the metalloids Si or P for the Co atoms. A complete EXAFS (Extended X-ray Absorption Fine Structure) analysis establishes that this chemical order induces a strong increase of the topological order in the vicinity of the Fe atoms. This ordered structure involves several coordination shells and is independent of the preparation method and of the nature of the metalloid (Si or P).
PACS: 61.10.Ht – X-ray absorption spectroscopy: EXAFS, NEXAFS, XANES, etc / 61.43.Dq – Amorphous semiconductors, metals, and alloys / 75.50.Kj – Amorphous and nanocrystalline magnetic materials; quasicrystals
© EDP Sciences, 1997